Our present invention relates to an electronic method and apparatus for pattern formation in a circular knitting machine.
Pattern formation in a circular knitting machine provided with an annular array of knitting needles around the outer periphery thereof has conventionally been accomplished by rotating the knitting machine so as to cause the knitting needles to make stitches at the desired actuators for actuating yarn feeders. In the pattern drum method for mechanically performing pattern formation, for example, the selection of needles has heretofore been accomplished by disposing a pattern drum for each actuator, planting pins on the outer peripheral surface in such a way as to constitute a memorized set of pattern signals, and employing a jack for grouping the knitting needles by pattern size.
In controlling the pattern formation in a circular knitting machine, a memory device stores all the pattern signals for the whole pattern to be knitted, even when it is composed of a plurality of small patterns of the same shape and size, and forwards the signals to each of the corresponding actuators disposed around the outer periphery of the circular knitting machine in synchronism with their read-out from the memory device.
In case the circular knitting machine is provided with a plurality of actuators for actuating yarn-feeders therearound in order to accelerate the knitting operation, and a signal course of pattern knitting is completed in one rotation of the machine, pattern signals must be fed for as many courses of knitting as there are groups of actuators. Consequently, the knitting mechanism becomes highly complex in signal-reading means, memory device, etc. There is a severe limit on the size of pattern to be formed and on the ease with which pattern modification can be accomplished.
Unlike the conventional method which forms knit patterns by mechanical means, the present invention is directed to an electronic method of pattern formation wherein all signals are first processed by a command device and then used to control the operation of needle actuators mounted on the circular knitting machine.